Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

Serenissima writes "Researcher Judy Wall is experimenting with bacteria that can cleanse the radioactivity from toxic areas by rendering the heavy metals into non-toxic, inert versions. The technology is not without its flaws (the bacteria can't exist in an oxygenated environment yet), but it does have the potential to cleanse some of the world's hazardous sites. From the article: 'The bacteria Wall is studying are bio-corrosives and can change the solubility of heavy metals. They can take uranium and convert it to uraninite, a nearly insoluble substance.'"

Of course they are not actually changing radioactive materials to non-radioactive materials - they change the compounds containing uranium to compunds that are very weakly soluble in water (instead of highly soluble), so they don't migrate easily. Very useful, but a little different from the impression I got from the summary.

There are two main reasons that you'd be concerned about chemical properties. One is just that a fair number of exciting radioisotopes are also chemically unpleasant. The second is that the chemical properties determine, in large part, how easy it is to keep the substance contained. An insoluble and largely unreactive material will be fine even if the barrel leaks a bit. A corrosive and water soluble material will make the barrel leak a bit and then start leaching into the water table. Radiation is bad; but isolating small areas of intense radioactivity is fairly easy. Isolating large areas of modest radioactivity that has a nasty habit of getting in the drinking water and being incorporated into your bones is quite difficult.

If a bacterial process can economically neutralize the material and induce it to stay where it is, rather than dissolving and floating around, that would make the problem smaller.

I'm no where near an expert on this stuff, but my understanding is that the big change is a soluble nasty material is made non-soluble.

In other words, that really nasty stuff likes to dissolve in water and spread everywhere, especially into the water table.

They want to make it not do that, so it's in a contained area, and might even be possible to extract it, or at least stopping it from making everything within a huge area into Chernobyl Nitelights.

I actually worked at a place that had to monitor this kind of stuff.Previous owners had 'disposed' of contaminated materials by buying them.Ironically, it wasn't the buried stuff that was the greatest risk factor to us.

I'm sure most of you, including icebike, probably understand this, but it seemed the perfect chunk of thread to post this.:)

Yup, doesn't change radioactivity at all. Despite heavy metal toxicity being a far bigger problem in terms of actual, real-world pollution, it just doesn't have the attention-grabbing aspects that radiation does.

The problem is the submitter and editor thought folks at slashdot would know what "inert" [wikipedia.org] means. Obviously, you and a few others didn't.

In chemistry, the term inert is used to describe something that is not chemically active. The noble gases were described as being inert because they did not react with the other elements or themselves. It is now understood that the reason that inert gases are completely inert to basic chemical reactions (such as combustion, for example) is that their outer valence shell is completely filled with electrons. With a filled outer valence shell, an inert atom is not easily able to acquire or lose an electron, and is therefore not able to participate in any chemical reactions. For inert substances, a lot of energy is required before they can combine with other elements to form compounds. High temperatures and pressure are usually necessary, sometimes requiring the presence of a catalyst.

For example, elemental nitrogen is inert under standard room conditions and exists as a diatomic molecule, N2. The inertness of nitrogen is due to the presence of the very strong triple covalent bond in the N2 molecule; nitrogen gas can, however, react to form compounds such as lithium nitride (Li3N) under standard conditions.

Inert atmospheres of gases such as nitrogen and argon are routinely used in chemical reactions where air sensitive and water sensitive compounds are handled.

"Inert" has absolutely nothing whatever to do with radioactivity, even though radioactive materials may or may not be inert.

I agree with you that it is a great picture, but as one who works with Dr. Judy Wall I can attest that she is definitely not the mad scientist type. The photographer put the camera inside an anaerobic chamber and then placed a blue background behind her outside the chamber to get the desired effect. Huge shame that the article was written by an idiot at the News Bureau and not by an actual scientist who could explain Judy's work.

Researchers should either write their own press releases or else not bother talking to the press at all.

I don't think you understand how this works at all. The researchers do research. The University has people on staff that are paid to publicize research. They try to understand the research as best they can. Then, they publicize it, trying to get the research all over the place, and THEY contact the press. If you are lucky (or unlucky, actually - it is a waste of time) the press may talk to you. The researchers are often several steps away from the reporters that report on it. I say this as a researcher who had research that I did at the University of Missouri (the university in question here) publicized, so I know how this works.

The process is pretty much completely beyond your control as a researcher. If the University wants to publicize your research, and they're going to do it regardless of what you say. You can't just not talk to your own university about your research.

To begin with, animals that reproduce sexually get an overwhelming majority of their genetic diversity from recombining genes from both parents. Random mutation, while present, is a minor factor in their evolution (how minor is a source of continued debate). All of your examples fall into this category.

Further, while they did likely mutate due to radiation at some point (you're quite right that the rate of radiation induced mutation is not zero), they don't meet the criteria of "harmless before, was mutated, now dangerous". Specifically, all of the examples you gave were apex predators, descended from a long line of large predatory animals, all of them likely dangerous.

In the case of the T-Rex, it's entirely possibly the species' ancestors were more dangerous, since Tyrannosaurs are generally thought to have been more opportunists than hunters - evolution made them less deadly, even as they got larger.

Anyway, I get your point that every extant species has at least some traits imparted by radiation induced mutation, and wasn't arguing otherwise. I merely wished to show that radiation isn't a relevant force in making otherwise harmless bacteria into pathogens, despite what Hollywood science has to say.